Abstract: A unified treatment of mass varying dark matter coupled to cosmon-{\em like}dark energy is shown to result in {\em effective} generalized Chaplygin gasGCG scenarios. The mass varying mechanism is treated as a cosmon fieldinherent effect. Coupling dark matter with dark energy allows for reproducingthe conditions for the present cosmic acceleration and for recovering thestability resulted from a positive squared speed of sound $c {s}^{\2}$, as inthe GCG scenario. The scalar field mediates the nontrivial coupling between thedark matter sector and the sector responsible for the accelerated expansion ofthe universe. The equation of state of perturbations is the same as that of thebackground cosmology so that all the effective results from the GCG paradigmare maintained. Our results suggest the mass varying mechanism, when obtainedfrom an exactly soluble field theory, as the right responsible for thestability issue and for the cosmic acceleration of the universe.